With both plants, we also really need to know if they are growing in cultivation or in the wild.

With both roses and apples/plums, there are a large number of species, hybrids and cultivars which make reliable ID difficult. At least if we know the plants are in the wild (and not just over the back fence of a garden), there is a much smaller world of possibilities.

I could not see any fruits for any of the plants, there alot of sweet chestnut trees in the area so the floor is completely covered in sweet chestnut cases and their leaves, as well as it being very muddy, I found it difficult to see anything on the floor.

These plants are from a small copse (about 18 acres). although some plants have been planted, I believe the vast majority are wild.

The presence of sweet chestnuts suggests the soil is acid (ie. not chalk or limestone). In this case, that does not help much.

If the area is close to a path, it is entirely possible that the apples/plums grew from seeds from fruit eaten and discarded by people passing by or stopping for a rest. The rose is more likely to be wild (though in some places, non-native shrubs are planted as cover for game birds; I have seen Symphoricarpos used like that).

If you make further observations in future, by all means post them on this thread.